Table 2.

Colorectal expression of p21, MIB-1, and hTERT during the clinical trial.

	Baseline				6-Months Follow-up				Absolute Rx Effect**				Relative Effect§	95% CI$		Pinteraction¤
	N	Mean	SE	P*	N	Mean	SE	P*	N	Mean	SE	P*
A. p21¥expression in colorectal crypts
Entirecrypts (LI)
Placebo	22	1.23	0.17		21	1.00	0.18		20	0.00			1.00
Calcium	23	0.85	0.17	0.11	21	1.37	0.18	0.14	21	0.78	0.33	0.03	2.01	1.08	3.72
Vitamin D	22	0.81	0.17	0.08	21	1.58	0.18	0.02	20	0.98	0.34	0.01	2.42	1.30	4.51
Ca + Vit. D	23	1.12	0.17	0.62	21	1.13	0.18	0.60	21	0.23	0.33	0.47	1.25	0.69	2.26	0.01
Upper 40% of crypts (LI40)
Placebo	22	1.10	0.15		21	0.91	0.16		20	0.00			1.00
Calcium	23	0.86	0.15	0.26	21	1.43	0.16	0.02	21	0.77	0.31	0.02	2.02	1.11	3.66
Vitamin D	22	0.77	0.15	0.13	21	1.54	0.16	0.01	20	0.96	0.31	0.00	2.44	1.31	4.53
Ca + Vit. D	23	1.02	0.15	0.70	21	1.09	0.16	0.43	21	0.26	0.31	0.41	1.29	0.71	2.34	0.004
B. MIB-1¥expression in colorectal crypts
Entire crypts (LI)
Placebo	22	1.01	0.10		21	1.00	0.10		20	0.00			1.00
Calcium	23	0.90	0.09	0.42	21	1.09	0.10	0.50	21	0.18	0.19	0.30	1.23	0.84	1.80
Vitamin D	22	0.83	0.10	0.18	22	1.08	0.10	0.58	22	0.25	0.19	0.18	1.32	0.89	1.96
Ca + Vit. D	23	1.25	0.09	0.09	21	1.10	0.10	0.49	21	−0.13	0.19	0.50	0.89	0.62	1.27	0.04
Ratio of upper 40% to entire crypts (φh)
Placebo	22	0.07	0.01		21	0.06	0.01		20	0.00			1.00
Calcium	23	0.09	0.01	0.40	21	0.07	0.01	0.64	21	−0.01	0.03	0.80	0.94	0.47	1.87
Vitamin D	22	0.08	0.01	0.56	22	0.07	0.01	0.71	22	−0.003	0.03	0.89	0.97	0.48	1.94
Ca + Vit. D	23	0.08	0.01	0.72	21	0.07	0.01	0.84	21	−0.003	0.03	0.92	0.97	0.48	1.97	0.68
C. hTERT¥expression in colorectal crypts
Entire crypts (LI)
Placebo	21	1.08	0.10		20	1.00	0.10		19	0.00			1.00
Calcium	22	1.01	0.10	0.63	20	1.00	0.10	0.99	19	0.07	0.21	0.73	1.07	0.72	1.59
Vitamin D	22	0.83	0.10	0.08	22	0.97	0.10	0.85	21	0.25	0.21	0.27	1.27	0.84	1.93
Ca + Vit. D	22	1.08	0.10	0.98	21	1.06	0.10	0.70	20	0.14	0.21	0.80	1.05	0.72	1.54	0.33
Ratio of upper 40% to entire crypts (φh)
Placebo	21	0.37	0.01		20	0.42	0.01		19	0.00			1.00
Calcium	22	0.39	0.01	0.33	20	0.39	0.01	0.24	19	−0.04	0.03	0.13	0.90	0.78	1.03
Vitamin D	22	0.37	0.01	0.81	22	0.41	0.01	0.63	21	−0.01	0.03	0.61	0.97	0.85	1.11
Ca + Vit. D	22	0.39	0.01	0.25	21	0.37	0.01	0.03	20	−0.07	0.03	0.02	0.85	0.74	0.98	0.93

^*P-value for difference between each active treatment group and placebo group from Mixed model. Covariates included random intercept, follow-up visit, treatment group, and treatment group by follow-up visit interaction.

^**Absolute treatment effect = ([treatment group follow-up - treatment group baseline] - [placebo group follow-up - placebo group baseline]); actual calculations from the Mixed model, in which the interactions between treatment group and follow-up visits terms estimate absolute treatment effect in each active treatment group relative to the placebo.

^§Relative effect = [(treatment group follow-up/treatment group baseline)/(placebo follow-up/placebo baseline)]; interpretation similar to that for an odds ratio (e.g., a relative effect of 1.8 would indicate a proportional increase of 80% in the treatment group relative to that in the placebo group).

^$95% confidence interval for relative effect calculated by the Delta method (24).

^¤P-value for interaction between calcium and vitamin D₃ treatments from Mixed model; covariates included random intercept, two factors (calcium and vitamin D₃ coded as 0/1 variable), follow-up visit, and all appropriate interaction terms between factors and follow-up visit.

^¥Biomarkers detected immunohistochemically and then their labeling densities were quantified by image analysis; all biomarkers values shown as batch-standardized optical densities. Batch standardization for each biomarker was performed by dividing each individual measurement by the staining batch’s average optical density.